Robert Downey Jr.'s Doctor Doom may have already made his MCU debut. A new fan theory suggests a Thunderbolts* scene was the hidden introduction of the MCU's next big bad, ahead of The Fantastic Four: First Steps and Avengers: Doomsday.
In the Thunderbolts* second post-credit scene, the New Avengers refer to a crisis in space before spotting a ship emblazoned with a "4" entering the Earth's atmosphere, all while Michael Giacchino's Fantastic Four score begins to swell. While fans assumed the ship was carrying Marvel's First Family and marked their MCU arrival, the new fan theory suggests RDJ's Victor Von Doom may actually be the one onboard.
While Doctor Doom is the MCU's next big bad and headlining Avengers: Doomsday, it's Galactus, not Doom, who's the primary villain of the July film (plus one other comic book antagonist). Therefore, if Doom is aboard the ship belonging to the Fantastic Four (and he didn't steal it), he may be working with them to reach Earth-616. If so, this could be a clever inverse of 2005's Fantastic Four movie, where Victor Von Doom funds and participates in the team's mission, but with the MCU flipping the concept with Doom pretending to be an ally or benefactor to achieve his goals.
Furthermore, news that Avengers: Doomsday directors, the Russo Brothers, directed the Thunderbolts* splashy tag supports this theory. And, so does Marvel Studios President Kevin Feige's eyebrow-raising comment (via Empire Magazine) where he cast doubt on the ship from the Thunderbolts* scene being the same from First Steps marketing, saying:
"Their ship is the Excelsior, and there is a Fantastic Four ship entering the MCU... But I'm not sure they’re the same ship."
Set to release on July 25, The Fantastic Four: First Steps is set within a retro, 1960s-inspired timeline. However, the film's cast, consisting of Pedro Pascal, Vanessa Kirby, Joseph Quinn, and Ebon Moss-Bachrach, is confirmed to appear in Avengers: Doomsday on December 18, 2026.
Find out what a Fantastic Four star said about working with RDJ's Doom here!
Why Doctor Doom's Thunderbolts* Arrival Is Best For Doomsday
One concern with Robert Downey Jr.'s Doctor Doom and Avengers: Doomsday (in addition to this confusing script rumor) is his villain's lack of build-up and connection, especially since he's not the villain of The Fantastic Four reboot. Introducing him early in Thunderbolts* and potentially as an ally in First Steps gives Marvel Studios room to develop his character before positioning him as the main antagonist in Doomsday.
It's also possible that Doom, not Reed Richards, may be the savior of The Fantastic Four: First Steps, and he employs his success with interdimensional and cosmic travel to become the MCU's new main antagonist. After all, the main villain of the Multiverse Saga needs to have established expertise when it comes to space, science, and the Multiverse (but is Marvel Studios planning to recast this Doom?)
If this fascinating theory proves true, Thunderbolts won’t just be a standalone anti-hero ensemble flick but rather the event when the MCU's next major villain enters the fray. Furthermore, if RDJ's Victor Von Doom is exploiting the Fantastic Four to reach the MCU, it instantly elevates him as a top-tier threat.
The Fantastic Four: First Steps arrives in theaters on July 25.
